By Lauriane Lognay

One of my favourite countries to visit for gem business is Tanzania. My last time there was exactly 11 years ago, and I knew the dissimilarities would be huge in 2024.

Tanzania is known for its rich deposits of gemstones, which play a significant role in the country’s economy. The country’s gemstone market is primarily centred around several key gems, such as tanzanite, garnet, tourmaline, diamonds, etc. This article will touch on a few famous Tanzanian gems and the country’s mining and market.

Always in-fashion

There are hundreds of gems found in Tanzania, but the most popular ones are:

Tanzanite

Perhaps the most famous gemstone associated with Tanzania, tanzanite is a blue to violet variety of the mineral zoisite. It was discovered in the 1960s in the Merelani Hills near the city of Arusha. Tanzania is the sole source of tanzanite in the world—making it highly valuable and unique. The tanzanite market can be quite volatile, influenced by factors like mining regulations, market demand, and the rarity of high-quality stones.

Garnets

Tanzania produces a variety of garnets, including deep red varieties (almandine and pyrope), green (grossular and tsavorite), and orange (spessartite). These are sourced from areas like the Umba Valley. Garnets are less rare than tanzanite but still significant in the market. You can find colour change garnets, imperial garnets, and UV-reactive garnets.

Tourmaline

Known for its wide range of colours, tourmaline is another important gemstone from Tanzania. The country produces several types of tourmalines, including the prized Paraiba tourmaline, which has a distinctive neon blue or green colour. You can also find amazing chrome tourmalines (deep green) and rubellites (red tourmaline).

Spinel

Tanzanian spinels come in a variety of colours, including red, pink, purple, grey, and blue. Spinel has been gaining recognition in the gemstone market due to its vibrant colours and durability. Mahenge spinels are famous for their quality and bright colours. The pink, red, and blue spinels are most in demand on the market. This stone is also a birthstone for August.

Sapphire

Although not as famous as tanzanite, Tanzania also has sapphire deposits, primarily in the areas around the town of Mafia Island and in the south near Songea. These sapphires can be found in various colours, including blue, pink, green, and yellow. Songea sapphires are well known for their deep saturated colour—which you can sometimes buy unheated.

Diamonds

Diamonds are also a big player in Tanzania due to the Williamson mine, which was discovered by a Canadian geologist in 1940. The open pit is famous for its high-quality pink and colourless diamonds. Diamonds in Tanzania are also artisanally mined, and the country is well known for its commercial quality and coloured diamonds.  

Regulation and challenges

The gemstone market in Tanzania is complicated, to say the least. Tanzanian laws have gotten stricter in the last few years. Having a local guide who knows where to go to buy the best gems, and can help you sift through all the bureaucracy, is paramount for a successful trip.

The gem market is regulated by the government to ensure fair practices and revenue collection. However, challenges such as illegal mining, smuggling, and fluctuating market prices can impact the industry.

One such government regulation concerns rough gemstone purchases. Purchases of facet quality tanzanite is limited to no more than one gram (five carats) per piece. For garnets, spinels, and other semi-precious gemstones of the same facet quality, the limit is two grams (10 carats) per piece. This is done to ensure the wealth generated from gemstone sales benefits local populations effectively and sustainably.

All rough gemstones heavier than the permitted two grams are to be faceted inside the country before being sold and exported. This makes it difficult for buyers to get good cuts, as most gems are cut for weight instead of quality. So, a heavier quality gem would have to be recut once home.

This law doesn’t apply to mineral specimens, which is why you can still see big, beautiful, rough tanzanite crystals outside of Tanzania. Stones that do not abide by these laws were either smuggled through Kenyan borders or old stock bought before the new laws were in place.

Quality and prices

I often hear from other dealers that getting good quality rough is difficult at the moment. Prices skyrocketed during COVID-19, and they don’t seem to be going down anytime soon.

Why? Why are stocks so low and quality so sparse? Why are prices so high? There are a lot of different economic and sociological explanations for these questions, but my take on the pre-pandemic and post-pandemic situation is:

• Before the pandemic, mining operations had never stopped. Supply and demand were stable, and years of gems were amassed and stocked. This is also why bigger parcels of high-quality goods were easier to find. Miners and companies alike had years to amass their gems and put parcels together. Old stock was on the market, mines were prospering, miners had hoards. Supply was much more than demand for most quality types.
• Small-scale miners and artisanal operations mine many Tanzanian gemstones. These miners often sell their finds to local traders, who then market them domestically or internationally. Gemstone mining provides significant employment opportunities and economic benefits for local communities.
• Most mines in Tanzania (artisanal and corporate) had to shut down activities in 2020. Some of them remained closed for the next two years, and only opened up their mining operations at the end of 2021 or 2022. During that time, as funds dwindled without activity, higher quality material was panic sold at lesser prices. Miners were emptying the goods they had amassed over the years—while people kept buying during the pandemic, no new material was coming out. Miners also had to sell to survive without jobs.
• So, old stocks, miner hoards, and parcels of all quality were sold with no replacement in sight for a period of two years. Demand was simply stronger than supply. People had more money to buy faceted goods and the rough was needed to keep up. This phenomenon can also explain some similar situations happening in other countries where mines had to be closed down.

Yet, despite everything, the dealers and miners I met during my trip were in good spirits, and coloured gems are still selling!

Dreams in colour

We are still seeing the damage the pandemic did to our market and will continue to see it for the next few years until stocks get back to normal. Estimates vary (as much as opinions do) but one thing is for certain: In an ever-changing market, coloured gemstones are still a sure bet for jewellery and fashion. They are in high demand and will continue to be with the affordability, rarity, durability, and range of colour they offer. Dream big, dream in colour!

Lauriane Lognay is a fellow of the Gemmological Association of Great Britain (FGA) and has won several awards. She is a gemstone dealer working with jewellers to help them decide on the best stones for their designs. Lognay is the owner of Rippana, Inc., a Montréal-based company working in coloured gemstone, lapidary, and jewellery services. She can be reached at rippanainfo@gmail.com.